[mythtv-users] thoughts on a combined backend/NAS box?

[Jim Oltman]

On Tue, Jul 16, 2013 at 3:37 AM, Tim Draper <veehexx at gmail.com> wrote:

> On 16 July 2013 06:55, GZ <gzornetzer.lists at gmail.com> wrote:
> > Hi all,
> > I've been thinking about upgrading my mythtv setup and at the same time,
> > I've also been looking at buying a RAID5 NAS box.  After looking at the
> > price tags on some of those enclosures, I'm thinking about just building
> a
> > combination RAID / mythbackend box.  I've read some of the guidance on
> the
> > wiki, indicating that RAID really isn't the best way to go for the mythtv
> > recording drive.  I'm thinking about the following drive setup:
> >
> > 1 SSD for the OS/database
> > 1x 1 tb for active recording (my existing recordings drive.  Eventually,
> I
> > may just upgrade this to a 3tb drive that would act something like an
> in-use
> > hot spare
> > 4x 3tb drives in RAID5 for archive storage (pictures / long-term video
> > archive)
> >
> > Since all of my tuners are now external (HDHR prime & usb QAM), I'm
> thinking
> > about a microitx motherboard to keep this box smallish (corner of my
> > office).  There are a few H77 boards with 6 total SATA ports an H87 board
> > with 6x 6gbps sata.  I figure that a 4-core ivy bridge or haswell process
> > has plenty of juice for this.
> >
> > Couple of things that I'd like to do:
> > - It would be cool to move shows from the recording drive to the archive
> > upon lossless transcode.  Do I have to write custom transcode rules to do
> > this?
> >
> > - I'd like to use ACPI wakeup to reduce power usage on this system.  This
> > means that I'm going to need some way to lock mythbackend when I want to
> use
> > the NAS functionality.  I suppose that I could run some mythfrontends on
> the
> > client, but that's pretty kludgy.  How complex is it to code up a client
> > that connects to mythbackend enough to bump the usage count and block
> > shutdown?  Alternatively, does anyone have a good way to trigger a
> > mythwelcome lock and unlock commands remotely over the network?
> >
> > Any advice or thoughts are welcomed.
> > Thanks very much,
> > -Greg
>

I'll just put out there that no one in their right mind should ever use
RAID5.  It's just not safe.  I'd recommend at least RAID6 or possibly
RAID10 if you're paranoid.  Remember, if a disk fails in RAID5, you need to
resilver the array.  That can take time.  What if another disk were to die
during the resilver?  You'd be screwed.  And don't think it won't happen to
you.  It happened to me.  It was awful.  Luckily, I managed to grab most of
my data.

That being said, I have an ESXi host that has 24 GB of RAM, a FreeNAS VM
with PCI Passthrough of 6 500GB SATA drives, and 2 2TB SAS drives.  FreeNAS
serves out an CIFS/NFS shares.  I've never had an issue with the RAIDZ2 or
Mirror I'm running.

Another VM is MythBackend dedicated and the third is an Ubuntu server
install for my Subsonic server.  (There have been numerous discussions this
past week on the value of straight up virtualization versus chroot.  I
won't get into it as I have a solution that works well for me.)  I really
like this setup.  However, since I have my NAS as a VM, and all clients on
my network require the NAS, the ESXi host is on all the time (along with
the APC SmartUPS 1500XL the host and 24 pt gig switch/pfSense Atom box/HD
HomeRun/AP/Cisco ASA are all connected to).  I've come to terms with the
electricity bills.

The only real issues I've run into are Ubuntu based ones.  For some reason,
I had unmet dependency troubles with the kernel image and header files ont
the virtualized machines.  I'm thinking I did something wrong, but I've
only ever tried to do the standard apt-get update/dist-upgrade.

Anyway, I'd virtualize if I were you.  Just my experience and 2 cents (or
pence, or whatever your local currency).

Jim
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